Heretofore, various processes have been employed for obtaining metallic iron by the reduction of iron-bearing sources such as ore. For example, U.S. Pat. No. 3,585,023 discloses a process in which iron ore is mixed with a reducing agent such as a fossil fuel and forming the mixture into agglomerates. The thus formed agglomerates are then charged to an enclosed environment which utilizes hot solid inert particles as the heating medium, said enclosed environment being maintained in the absence of oxygen. Upon completion of the desired reduction, the particles and agglomerates are separated and the reduced agglomerates are allowed to partially cool before being exposed to the atmosphere. Following this, the reduced agglomerates are then recovered. Other methods utilize a heating and magnetic separation to effect a production of iron powder as well as effecting a physical separation by crushing, scalping, air cleaning, and screening, followed by subjecting the ore to a high intensity induced magnetic field. U.S. Pat. No. 2,728,655 discloses a method for producing iron powder with a low silica content in which an iron-containing material in finely divided form is admixed with a solid ash-containing carbonaceous reducing agent. The mixture is then heated to complete the reduction of the iron-containing material followed by cooling and recovery of the iron content.
As will hereinafter be shown in greater detail, it has now been discovered that by subjecting the iron-bearing source to a series of steps, it is possible to obtain an iron powder which will contain less than 0.1% silica, which is considerably less than the silica content of iron which remains after the normal treatment of iron-bearing sources.